Ptosis and Miosis Associated with Fibrosing Mediastinitis.

BACKGROUND Fibrosing mediastinitis is a rarely seen, progressive disease. It results from an excessive fibrotic reaction in the mediastinum. We describe a presentation of fibrosing mediastinitis that, to our knowledge, has never been seen before. CASE REPORT A 30-year-old female Colombian flight attendant presented with a right eyelid droop. Examination revealed partial right-sided ptosis and miosis but no anhidrosis. An ill-defined firm swelling was palpable at the root of the neck. Chest radiography revealed a widened mediastinum, and computerized tomography (CT) showed a right paratracheal mass without calcification extending to the thoracic inlet, encasing multiple blood vessels. All basic blood tests, magnetic resonance imaging of the head, and ultrasound Doppler of the neck vessels were normal. History and work up for infections including fungal diseases, granulomatous diseases, vasculitis, and autoimmune diseases were negative. Positron emission tomography (PET) showed significant FDG uptake in the mediastinum. Mediastinal biopsy was histologically consistent with fibrosing mediastinitis. All relevant immunohistochemistry and microbiological studies were negative. Subsequently, the patient developed signs of superior vena cava compression; this was managed by balloon angioplasty, which resulted in improvement of symptoms. However, over time, her symptoms worsened progressively, resulting in a left-sided ptosis and radiological progression of the mass on CT. She received treatment with rituximab and concomitant steroids, which yielded excellent results: the treatment led to both resolution of her symptoms and regression of the mass and its metabolic activity on PET scan. CONCLUSIONS Fibrosing mediastinitis can present with an incomplete Horner's syndrome. Treatment with rituximab and steroids shows promising results in select cases of metabolically active idiopathic fibrosing mediastinitis.

CFTR modulator therapy for cystic fibrosis caused by the rare c.3700A>G mutation.

BACKGROUND: The c.3700A>G mutation, a rare cystic fibrosis (CF)-causing CFTR mutation found mainly in the Middle East, produces full-length transcript encoding a missense mutation (I1234V-CFTR), and a cryptic splice site that deletes 6 amino acids in nucleotide binding domain 2 (I1234del-CFTR). METHODS: FRT cell models expressing I1234V-CFTR and I1234del-CFTR were generated. We also studied an I1234del-CFTR-expressing gene-edited human bronchial (16HBE14o-) cell model, and primary cultures of nasal epithelial cells from a c.3700A>G homozygous subject. To identify improved mutation-specific CFTR modulators, high-throughput screening was done using I1234del-CFTR-expressing FRT cells. Motivated by the in vitro findings, Trikafta was tested in two c.3700A>G homozygous CF subjects. RESULTS: FRT cells expressing full-length I1234V-CFTR had similar function to that of wildtype CFTR. I1234del-CFTR showed reduced activity, with modest activation seen with potentiators VX-770 and GLPG1837, correctors VX-809, VX-661 and VX-445, and low-temperature incubation. Screening identified novel arylsulfonyl-piperazine and spiropiperidine-quinazolinone correctors, which when used in combination with VX-445 increased current ~2-fold compared with the VX-661/VX-445 combination. The combination of VX-770 with arylsulfonamide-pyrrolopyridine, piperidine-pyridoindole or pyrazolo-quinoline potentiators gave 2-4-fold greater current than VX-770 alone. Combination potentiator (co-potentiator) efficacy was also seen in gene-edited I1234del-CFTR-expressing human bronchial epithelial cells. In two CF subjects homozygous for the c.3700A>G mutation, one subject had a 27 mmol/L decrease in sweat chloride and symptomatic improvement on Trikafta, and a second subject showed a small improvement in lung function. CONCLUSIONS: These results support the potential benefit of CFTR modulators, including co-potentiators, for CF caused by the c.3700A>G mutation.